ACS Synthetic Biology
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2021
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IF 5.11
Yang Li,Zhenzhen Cheng,Chunlei Zhao,Cong Gao,Wei Song,Liming Liu,Xiulai Chen
The recycle and reutilization of food wastes is a promising alternative for supporting and facilitating circular economy. However, engineering industrially relevant model organisms to use food wastes as their sole carbon source has remained an outstanding challenge so far. Here, we reprogrammed Escherichia coli metabolism using modular pathway engineering followed by laboratory adaptive evolution to establish a strain that can efficiently utilize waste cooking oil (WCO) as the sole carbon source to produce monomers of bioplastics, namely, medium-chain α,ω-dicarboxylic acids (MCDCAs). First, the biosynthetic pathway of MCDCAs was designed and rewired by modifying the β-oxidation pathway and introducing an ω-oxidation pathway. Then, metabolic engineering and laboratory adaptive evolution were applied for improving the pathway efficiency of fatty acids utilization. Finally, the engineered strain E. coli AA0306 was able to produce 15.26 g/L MCDCAs with WCO as the sole carbon source. This study provides an economically attractive strategy for biomanufacturing bioplastics from food wastes, which has a great potentiality to be developed as a wide range of enabling biotechnologies for achieving green revolution.
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Scientific Reports
·
2021
·Vol. 11
·期 1
·1-9
·
IF 4.38
Li Danqing,Chen Shuai,Zhang Ke,Gao Nan,Zhang Miao,Albasher Gadah,Shi Jiangfan,Wang Chuanyi
Silver-based antibacterial agents have obtained wide attention due to the fact that bacteria in the environment is ubiquitous, which has become one of the most difficult problems for human health. However, the antibacterial mechanism and process are still inconclusive. Here, Ag 2 O nanoparticles (NPs) with uniform spherical morphology and small size (around 30 nm) were prepared. The as-prepared Ag 2 O NPs induced high antibacterial activity (100% inhibition ratio) against E. coli . A two-step antibacterial process was proposed and confirmed, which divided into inhibition and sterilization steps. The optical density measurement, malondialdehyde concentration detection, morphologic imaging with electronic microscopy and Fourier transform infrared spectroscopic analysis unveiled the interaction of Ag 2 O NPs with E. coli , which verified the inhibition–sterilization process we proposed.
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BIOCHEMICAL ENGINEERING JOURNAL
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2020
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IF 3.475
Guohui Li,Dixuan Huang,Li Wang,Yu Deng
Putrescine is an amine with high industrial value. At present, the chemical production method used in industry has shortcomings of using unsustainable petroleum raw material and expensive reaction catalyst, unsafe reaction process with inflammables and explosives. Therefore, researchers turn their attention to the biosynthesis of putrescine. Escherichia coli , with the natural pathway for the synthesis of putrescine, is a good choice for producing putrescine as the host strain. In this study, an effective putrescine bio-production platform was built via overexpressing two key pathway enzymes in engineered Escherichia coli PUT2, combining with a well-controlled fermentation strategy. Escherichia coli PUT2 converted arginine to putrescine within 48 h on a 3 L scale, reaching a titer of 26.21 g L −1 , and the specific production of putrescine was 1.99 g per unit biomass, with a productivity of 0.54 g L -1 h -1 , which obtained the high production efficiency of cell. Compared with the original strain Escherichia coli BL21(DE3), the putrescine titer increased to 79 times. This research offered a promising strategy for putrescine bio-synthesis, laying a foundation for large-scale putrescine bio-production.
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Food Bioscience
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2020
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IF 3.067
Hong Yan,Yingying Lu,Xin Li,Yanglei Yi,Xin Wang,Yuanyuan Shan,Bianfang Liu,Yuan Zhou,Xin Lü
Bacteriocins have potential in the food industry, especially in protecting food safety and controlling food-borne diseases. Class II bacteriocin genes were previously identified from the genome of Lactobacillus crustorum MN047 and successfully expressed in Escherichia coli BL21 (DE3) using the pET-30a system. In this study, the antibacterial mechanism and potential use as a food preservative were studied. The results showed that bacteriocin BM1829 had antimicrobial activity against Gram-positive and Gram-negative bacteria with MIC values of 1–16 mg/L. In addition, BM1829 showed good stabilities to chemicals, and to thermal and pH changes. BM1829 destroyed the integrity of membranes and led to the leakage of cytoplasmic content. Flow cytometry showed that BM1829 arrested the cell cycle at R-phase. Moreover, the number of E. coli and Staphylococcus aureus cells was reduced during beef storage with BM1829 treatment. These data suggested that BM1829 has the potential to be developed as a food preservative or antibacterial agent.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
·
IF 4.192
Yanan Hou,Xue Liu,Shilin Li,Xue Zhang,Sili Yu,Guang-Rong Zhao
Betalains are emerging natural pigments with high tinctorial strength and stability, physiological activities, and fluorescent properties for potential application in food, cosmetic, and pharmaceutical industries. Betalains including yellow betaxanthins and red betacyanins are mainly restricted in the Caryophyllales plants. To expand the availability of individual betaxanthins, here, we constructed an Escherichia coli BTA6 for de novo biosynthesis of betalamic acid. Using this strain as a monoculture platform, 14 yellow and 2 red betaxanthins were produced by feeding amino acids and amines. Furthermore, we constructed an l-histidine overproducing strain using chromosome engineering to deattenuate regulation and established a coculture system. After optimization of the initial inoculation ratios and fermentation conditions, the compatible and robust coculture system produced 287.69 mg/L of histidine-betaxanthin. This is the first report on de novo production of betaxanthins in engineered E. coli using glucose as a carbon source. Our work highlights the feasibility of microbial cell factories to produce individual betalains.
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ARCHIVES OF MICROBIOLOGY
·
2018
·Vol. 201
·期 4
·451-458
·
IF 1.607
He Tian-Fu,Wang Lang-Hong,Niu De-bao,Wen Qing-hui,Zeng Xin-An
In this study, the antimicrobial mechanism of cinnamaldehyde (CIN) against Gram-negative Escherichia coli ATCC 25922 ( E. coli ) based on membrane and gene regulation was investigated. Treatment with low concentration (0, 1/8, 1/4, 3/8 MIC) of CIN can effectively suppress the growth of E. coli by prolonging its lag phase and Raman spectroscopy showed obvious distinction of the E. coli after being treated with these concentration of CIN. The determination of relative conductivity indicated that CIN at relatively high concentration (0, 1, 2, 4 MIC) can increase the cell membrane permeability, causing the leakage of cellular content. Besides, the content of malondialdehyde (MDA) and the activity of total superoxide dismutase (SOD) of E. coli increased with increasing treatment concentration of CIN, implying that CIN can cause oxidative damage on E. coli cell membrane and induce the increase of total SOD activity to resist this oxidative harm. Moreover, quantitative real-time RT-PCR (qRT-PCR) analysis revealed the relationship between expression of antioxidant genes (SODa, SODb, SODc) and treatment CIN concentration, suggesting that SOD, especially SODc, played a significant role in resistance of E. coli to CIN. The underlying inactivation processing of CIN on E. coli was explored to support CIN as a potential and natural antimicrobial agent in food industry.
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JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY
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2016
·Vol. 43
·期 4
·557-566
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IF 2.745
Cao Weijia,Ma Weichao,Zhang Bowen,Wang Xin,Chen Kequan,Li Yan,Ouyang Pingkai
The development of efficient microbial processes for pinocembrin production has attracted considerable attention. However, pinocembrin biosynthetic efficiency is greatly limited by the low availability of the malonyl-CoA cofactor in Escherichia coli. Fatty acid biosynthesis is the only metabolic process in E. coli that consumes malonyl-CoA; therefore, we overexpressed the fatty acid biosynthetic pathway enzymes β-ketoacyl-ACP synthase III (FabH) and β-ketoacyl-ACP synthase II (FabF) alone and in combination, and investigated the effect on malonyl-CoA. Interestingly, overexpressing FabH, FabF or both enzymes in E. coli BL21 (DE3) decreased fatty acid synthesis and increased cellular malonyl-CoA levels 1.4-, 1.6-, and 1.2-fold, respectively. Furthermore, pinocembrin production was increased 10.6-, 31.8-, and 5.87-fold in recombinant strains overexpressing FabH, FabF and both enzymes, respectively. Overexpression of FabF, therefore, triggered the highest pinocembrin production and malonyl-CoA levels. The addition of cerulenin further increased pinocembrin production in the FabF-overexpressing strain, from 25.8 to 29.9 mg/L. These results demonstrated that overexpressing fatty acid synthases can increase malonyl-CoA availability and improve pinocembrin production in a recombinant E. coli host. This strategy may hold promise for the production of other important natural products in which cellular malonyl-CoA is rate limiting.
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ACS Nano
·
2024
·
IF 15.8
Wei Zhou,Wen Zhang,Wei Geng,Yaoqi Huang,Tong-Kai Zhang,Zi-Qian Yi,Yang Ge,Yao Huang,Ge Tian,Xiao-Yu Yang
External electric field has the potential to influence metabolic processes such as biological hydrogen production in microorganisms. Based on this concept, we designed and constructed an electroactive hybrid system for microbial biohydrogen production under an electric field comprised of polydopamine (PDA)-modified Escherichia coli (E. coli) and Ni foam (NF). In this system, electrons generated from NF directly migrate into E. coli cells to promote highly efficient biocatalytic hydrogen production. Compared to that generated in the absence of electric field stimulation, biohydrogen production by the PDA-modified E. coli-based system is significantly enhanced. This investigation has demonstrated the mechanism for electron transfer in a biohybrid system and gives insight into precise basis for the enhancement of hydrogen production by using the multifield coupling technology.
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ACS Synthetic Biology
·
2025
·
IF 3.9
Zheng Lei,Jinyong Wu,Caiwen Lao,Jin Wang,Yanyi Xu,He Li,Lixia Yuan,Xiangsong Chen,Jianming Yao
Ectoine is an important natural macromolecule protector that helps extremophiles maintain cellular stability and function under high-salinity conditions. Recently, the development of microbial strains for high-level ectoine production has become an attractive research direction. In this study, we constructed an efficient plasmid-free ectoine-producing strain. We modified the 5′-untranslated region of the ectABC gene cluster from Halomonas elongate to fine-tune the expression of genes ectA, ectB, and ectC. Furthermore, we optimized the carbon flow across the MEP pathway, the TCA cycle, and the aspartic acid metabolic pathway. Subsequently, we blocked the production of byproducts from the aspartic acid metabolic pathway and dynamically regulated the TCA cycle to coordinate the balance between strain growth and production. The final strain was tested in a 5-L fermenter, which reached 118.5 g/L at 114 h of fermentation. The metabolic engineering strategies employed in this study can be used for the biosynthesis of other aspartate derivatives.
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CHEMBIOCHEM
·
2025
·
IF 2.8
Shiqi Luo,Wei Song,Guipeng Hu,Jian Wen,Xiaomin Li,Cong Gao,Jia Liu,Wanqing Wei,Liming Liu
Graphical Here, we have constructed a dual-enzyme ( Ec TnaA, Ma FMO) cascade pathway for the biosynthesis of indigo from L-tryptophan and enhanced the enzymatic activity of Ma FMO through mechanism-guided rational design. Subsequently, by optimizing promoters and increasing copy numbers to regulate the expression levels of Ec TnaA and Ma FMO D197E , under optimal conditions, E. coli IND-13 achieved the highest yield to date using glucose as the substrate. Indigo is widely used in dyes, medicines and semiconductors materials due to its excellent dyeing efficiency, antibacterial, antiviral, anticancer, anti-corrosion, and thermostability properties. Here, a biosynthetic pathway for indigo was designed, integrating two enzymes ( Ec TnaA, Ma FMO) into a higher L-tryptophan-producing the strain Escherichia coli TRP. However, the lower catalytic activity of Ma FMO was a bottleneck for increasing indigo titers. To overcome this limitation, the enzyme activity of Ma FMO was enhanced through mechanism-guided rational design. The optimal mutant obtained in this study, Ma FMO D197E , whose k cat / K m was 1.34 times that of the wild type, and its specific activity was 2.36 times that of the wild type. In addition, the expression levels of Ec TnaA and Ma FMO D197E were regulated by optimizing the promoters and increasing the copy number to generate the strain E. coli IND-13. Finally, in the optimal fermentation conditions (220 rpm, 0.05 % Tween-80), the strain E. coli IND-13 achieved the indigo titer of 568.52 mg/L in a 5-L bioreactor, with the yield and productivity of 2.62 mg/g and 12.96 mg/L/h (the highest to date), respectively. The results presented here can lay a foundation for further construction of cell factories for indigo and its derivatives with industrial application potential.
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ACS Synthetic Biology
·
2025
·
IF 3.9
Zheng Lei,Xiangsong Chen,Lixia Yuan,Jinyong Wu,Jianming Yao
Ectoine is a pivotal natural osmoprotectant that functions as a compatible solute through osmoregulation, enabling microorganisms to thrive in extreme environments such as high salinity. To meet market demands, this study focuses on optimizing its production process. We initially engineered the ectABC gene cluster from Halomonas venusta via 5′-UTR modification, establishing a functional ectoine biosynthesis pathway in E. coli. Subsequent introduction of a rate-limiting enzyme EctB mutant (E407D) and aspartokinase mutant increased titer by 140%. To address lysine byproduct accumulation, an innovative molecular switch was employed to regulate lysA gene expression, achieving dynamic balance between cell growth and product synthesis. Further optimization through cofactor engineering yielded the final strain ECT31, which produced 164.6 g/L ectoine in a 100 L bioreactor within 117 h, the highest reported titer for E. coli-based ectoine production to date. The metabolic engineering strategy presented herein establishes a new pdigm for efficient biosynthesis of amino acid derivatives.
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ACS Synthetic Biology
·
2024
·
IF 3.7
Chenghu Chen,Cong Gao,Guipeng Hu,Wanqing Wei,Xiaoge Wang,Jian Wen,Xiulai Chen,Liming Liu,Wei Song,Jing Wu
Salicylate plays a pivotal role as a pharmaceutical intermediate in drugs, such as aspirin and lamivudine. The low catalytic efficiency of key enzymes and the inherent toxicity of salicylates to cells pose significant challenges to large-scale microbial production. In this study, we introduced the salicylate synthase Irp9 into an l-phenylalanine-producing Escherichia coli, constructing the shortest salicylate biosynthetic pathway. Subsequent protein engineering increased the catalytic efficiency of Irp9 by 33.5%. Furthermore, by integrating adaptive evolution with transcriptome analysis, we elucidated the crucial mechanism of efflux proteins in salicylate tolerance. The elucidation of this mechanism guided us in the targeted modification of these transport proteins, achieving a reported maximum level of 3.72 g/L of salicylate in a shake flask. This study highlights the importance of efflux proteins for enhancing the productivity of microbial cell factories in salicylate production, which also holds potential for application in the green synthesis of other phenolic acids.
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